Mechanical time fuzes, particularly for a submarine explosive charge



April 24, 1962 R. SIMMEN ET AL 3,030,887

MECHANICAL TIME FUZES, PARTICULARLY FOR A SUBMARINE EXPLOSIVE CHARGEFiled Dec. 31 1959 4 Sheets$heet l Fla. 1

I/NVE/VTOIES S/MMEN ,QoBE/e 49d EA 'M 141911124, 1962 R. SIMMEN ET AL3,030,887

MECHANICAL TIME FUZES, PARTICULARLY FOR A SUBMARINE EXPLOSIVE CHARGE 4Sheets-Sheet 2 Filed Dec. 51 1959 yyygwrae 5 QBEQT /M- EH/Vs M O REA.

April 24, 1962 Filed Dec. 31, 1959 R. SIMMEN ET AL MECHANICAL TIMEFUZES, PARTICULARLY FOR A SUBMARINE EXPLOSIVE CHARGE 4 Sheets-Sheet 3April 1962 l R. SIMMEN ET AL 3,030,887

MECHANICAL TIME FUZES, PARTICULARLY FOR A SUBMARINE EXPLOSIVE CHARGEFiled Dec. 51, 1959 4 Sheets-Sheet 4 United States Patent 3,030,887MECHANICAL TIME FUZES, PARTICULARLY FOR A SUBMARINE EXKLOSIVE CHARGERobert Simmen and Ren Morel, Geneva, Switzerland,

assignors to Mefina S.A., Fribourg, Switzerland Filed Dec. 31, 1959,Ser. No. 863,327 Claims priority, application Switzerland Jan. 17, 19598 Claims. (Cl. 102-84) The present invention has for its object amechanical time fuze, particularly for a submarine explosive charge,comprising a detonator capable of being fired by a striker loaded by aspring, said striker being maintained in a safe position by a lockingdevice of which the release is controlled by a clockwork movement aftertiming the fuze.

The mechanical time fuze according to the invention is characterised inthat the locking device comprises a bolt located in the interior of twoindependent coaxial parts, each having an opening, said openings beingdisplaced in safe position for preventing the release of the bolt, theclockwork movement controlling one of the two independentcoaxial partsfor bringing the said openings in coincidence after a time given by thetiming, one of these two coaxial parts being secured to a timing shaftcapable of being moved angularly and axially and of which one endcarries an operating member, a device for locking the clockwork movementbeing controlled by said timing shaft, a safety device preventing axialmovement of the said shaft in view of the unlocking of the clockworkmovement only after an angular movement of this determining apredetermined timing.

One form of construction of the fuze according to the invention is showndiagrammatically and by way of example in the accompanying drawings,wherein:

FIG. 1 is a view in axial section of said fuze.

FIG. 2 is a plan-view.

FIG. 3 is a section on the line III-III of FIG. 1.

FIG. 4 is a section on the line IVIV of FIG. 1.

FIG. 5 is a section on the line V-V of FIG. 1.

FIG. 6 is a section on the line VI-VI of FIG. 1, showing a primer safetywith which the fuze is provided, said primer safety being shown in thesafe position.

FIG. 7 is a view similar to the preceding one, said primer safety beingreleased.

This mechanical time fuze, particularly for a submarine explosivecharge, comprises a fuze body 1 adapted to be screwed into the shell 2of the explosive charge. This fuze body -1 carries a fuze sheath 3 heldthereon by means of screws 4 and with the interposition of a fluid-tightlining 5. Said fuze body and sheath 3 constitute a casing which enclosesthe whole mechanism thereof.

In proximity to the primary explosive charge in shell 2, there is formeda well in which is located the detonator 6 secured to a first plate 7.Between this plate 7 and a second plate 8 is located a safety deviceconstituted by a movable support 9 hinged about a spindle 10 disposedeccentric to the axis of the casing and subjected to the action of aspring 11. Said support 9 carries a primer 12 (see FIGS. 1, 6 and 7)adapted to be maintained spaced from the detonator 6 and from thetrajectory of the point of a firing pin 13 located in the axis of thecasing, while the fuze has not been timed and released.

This pin 13 is disposed in a central socket portion 14 of a time settingshaft 15 which is angularly and axially movable. As shown, this pin 13has a medial collar 16 and a spring 17 is coiled about the portion ofthe stem of the pin in the socket and is confined between the botton ofthe socket portion 14 and the collar 16 to bias the pin to firingposition. i

The pin. 13 is held in a safe the load of its spring '17, by a detent orlocking device whose release is controlled by a clockwork movementindiposition, notwithstanding Patented Apr. 24-, 1962 cated generally bythe reference 18. This clockwork movement 18 is secured to three plates,namely the second plate 8, a third plate 19 and a fourth plate 20.

Between the plates 8 and 19 is disposed the spiral motor spring 21 ofthe clockwork. This spring has its outer end anchored to the plates 8and 19, while the inner end is adapted to entrain a hollow shaft 22.This hollow shaft 22 is extended upwardly in such a manner as totelescope the lower end of the manually manipulatable time setting shaft15. Thus it may be said that 15 and 22 constitute a two-part timingshaft assembly, the outer part, or selectively settable section, beingcapable of manual rotation and axial movement while the inner clockcontrolled section 22 is fixed against axial movement because it ismounted between the third and fourth plates 19 and 20 only to be drivenby the clockwork.

. The hollow clock shaft 22 carries a principal toothed wheel 23driving, through the medium of a gear train 24 to 27, an escapementwheel 28 (see FIGS. 1 and 5). The movements of said escapement wheel 28are controlled by a balance 29 provided with a spiral spring 30, thebalance carrying a pin 31 cooperating with a fork 32 controlling themovements of the anchor 33. The spindle 34 of the balance 29 is providedwith a notch 35 for the passage of the end of the fork 32 during each ofits movements of oscillation produced by the entrance of the pin 31 intothe slot 36 of the fork 32.

The locking device of the firing pin 13 comprises a bolt formed, in theparticular case, by a ball 37 located in the interior of two independentcoaxial parts 38 and 39. The internal part 38 is constituted by theinner end of the timing shaft 15, whilst the external part 39 isconstituted by the adjacent end of the hollow shaft 22 which surroundsthe time setting shaft 15 over a predetermined portion of its length.The part 38 has an opening 40, in which is engaged the ball 37. Asregards the part 39, this has an opening 41, displaced axiallyrelatively to the opening 40 in the safe position of the fuze, forpreventing the release of the firing pin 13 by radial escape of the ballthrough the openings 40 and 41.

To the time setting shaft 15 is secured a cross bar 42 carrying a rod 43constituting means for locking and releasing the balance 29. In fact, inthe safe position of the fuze the end 44 of said rod 43 engages in ahole 45 provided in the balance 29. A spring 46 fitted around the rod 43tends to repel this in such a manner as to maintain the end 44 in thehole 45 of the balance 29. Further, a spring 47, confined between thecross bar 42 and a fifth plate 48 hearing against the body 1, tends tomaintain the time setting shaft 15 in the safe position.

Flexible linings 49 ensure fluidtightness between the body 1 and thetime setting shaft 15. Said latter carries at its outer end an operatingmember or knob 50. This operating member 50 is secured preferably in adetachable manner to the outer end of the time setting shaft 15 in sucha manner as to be separated from said shaft once the timing has beeneffected and after the shaft has been pulled axially towards theoutside. For this purpose, the operating member 50 includes a button Bwhose shank 51 is engaged axially in the time setting shaft 15. A detent52 is fitted in a radial bore 53 of the shaft 15, in such a manner thatits inner end 54, which is conical, penetrates into a notch 55 of theshank 51 so as to render this solid with the time setting shaft 15.After axial movement of the shaft 15 towards the outside, by tractionapplied to the operating knob 50 after a predetermined, angular movementhas been imparted thereto, the detent 52 is adapted to be Withdrawnradially so as to release the stem 51 and thus the operating member 50.The detent 52 then engages with a notch 56 in such a manner as to lockthe time setting shaft 15 in the cocked position.

The time setting shaft 15 is also angularly secured to a timing disc 57engagmg in a recess 58 of the body 1. Said disc 57 is provided with aprojection 59 penetrating into a longitudinal groove 60 of the shaft 15,in such a manner as to provide for completely free axial movement ofsaid shaft 15. The timing disc 57 is maintained against the body 1 bymeans of a washer 61 embedded into the body 1. Said washer 61 carriestime graduations 62 (see FIG. 2).

The timing disc 57 is maintained in a safe position by two lockinglevers 63 located partly in a circular groove 64 of the body 1. Theinner end 65 of each lever 63 passes through an opening 66 and engagesunder the action of a spring 67, with fine teeth 68 provided at theperiphery of the disc 57. The outer end 69 of each lever 63* passes tothe outside of the body 1 through an opening 79. The release of thetiming disc 57 is thus efiected by pressing the extremities 69 of thetwo levers 63 in such a manner as to disengage the extremities 65 fromthe teeth 68 of the disc 57.

Said fuze also comprises a safety device only permitting of axialmovement of the time setting shaft for the purpose of releasing theclockwork movement 18 after an angular displacement has been imparted tothe said shaft, which displacement determines a predetermined timing.This safety device is constituted by the offset safety lip or edge 72 atthe inner bight of a U-shaped slot 72 provided in the fixed fifth plate43, through which U- shaped slot 72 passes the time setting shaft 15. Agroove 73- is cutaround the shaft 15, in such a manner as to form aprojection or shoulder 74 to subsist. Said projection 74 cooperates withthe lip edge 71 of the fifth plate for maintaining the time settingshaft 15 in safe axial position. However, it will be readily understoodfrom a study of FIG. 3 that any angular movement of about of the shaft15 in opposite directions from its central position, permits of itmoving axially, the lip or edge 71 only retaining the shoulder 74 over arelatively small angle.

The maintenance of the movable support 9 of the primer 12 in the safeposition against the action of its spring 11- is obtained by arestraining tooth 75 which is provided at the end of the hollow shaft 22opposite to that in which the time setting shaft 15 is engaged (seeFIGS. 1 and 6).

The functioning of the mechanical time fuze hereinbefore described withreference to the accompanying drawing, takes place in the followingmanner:

In the safe position the members of the fuze are located in the positionshown in FIGS. 1 to 6, that is to say the ball 37 locks the firing pin13, the rod 43 locks the balance 29, the tooth 75 retains the movableprimer support 9 in the position shown in FIG. 6, and the levers 63maintain the timing disc 57 in the position shown in FIG. 2.

When it is desired to time the fuze, the ends 69 of the levers 63 arepressed between two fingers for releasing the timing disc 57. It is thenpossible to rotate said disc 57 by means of the operating knob 56 and tobring the mark 76 opposite any point of the graduation 62, according tothe desired interval of retardation of the explosion of the chargecontrolled by the fuze. The graduation 62 indicates, by way of example,in minutes, the time of retardation which it is possible to selectbetween 15 and 120 minutes. By setting the operatin knob 50 in rotation,the internal part 38 is displaced angularly relatively to the coaxialpart 3?, which spaces the openings and 41 by a predetermined angle,namely an angle corresponding to the degree of timing indicated on thescale 62.

When the timing has thus been effected, the operator applies an axialpull on the operating knob 50, thus moving the time setting shaft 15towards the outside, whereby the rod 43 is moved therewith, the end 44thereof leaving the hole and releasing the balance 29. As a result theclockwork movement 18 is set in operation.

The axial movement which has been imparted to the shaft 15 has broughtinto the same plane the openings 40 and 41 of the two coaxial parts 38and 39. At the end of this axial movement of the shaft 15, the detent 52releases the shank 51 of the button B which detaches itself from theshaft 15 and this detent 52 locks the shaft 15 in the armed position. Byreason of the separation of the operating knob 50, the operator takesfully into account that the fuze is armed and is in operation for firingthe explosive charge which it controls. The operator therefore movesaway from the charge.

After a period of operation of the clockwork movement 18 permitting of arotation of about 30 of the hollow shaft 22, the retaining tooth 75releases the movable support 9 and the spring 11 moves the primer 12into proximity of the detonator 6 on the trajectory of the striker 13.When the complete time setting has expired, the opening 41 of the part39 is brought into coincidence with the opening 40' of the coaxial part38. The ball 37, under the action of the collar 16 with a conical edge,collar urged by the spring 17, is forced radially through the openings40 and 41 and releases the striker 13. The striker 13, urged by itsspring 17, fires the primer 12 and consequently the detonator 6, as alsothe complete explosive charge;

The foregoing description shows that this mechanical time fuze is ofatparticularly safe manipulation, which is very advantageous in thepainful conditions under which the operators must manipulate them,particularly when these operators must manipulate them under water.

It is to be observed that the driving in rotation of the timing disc 57may be effected either in one direction or the other. Thus a timing ofminutes, for example, may be effected very rapidly, also a rapidly as atiming of 15 minutes.

Numerous variations in construction of the fuze hereinbefore describedmay be imagined. Thus, the operating knob 50 need not be made detachablefrom the shaft 15. Further, this fuze need not be provided with theprimer safety device 9 to 12. As regards the coaxial parts 38 and 39,instead of forming an integral part of the timing shaft 15 and the motorshaft 22 of the clockwork movement respectively, they may form part ofparts controlled by these two shafts 15 and 2'2.

Another advantage of the fuze hereinbefore described resides in the factthat the conditions of operation of the driving spring 21 of theclockwork movement 18 are independent of the frictional forces which mayexist between the timing shaft 15 and fluidtight linings 49, forexample, in view of the fact that this spring 21 does not drive saidshaft 15 used solely for the timing and the setting in operation of theclockwork movement 18.

We claim:

1. A mechanical timing fuze for an explosive submarine charge,comprising, in combination, a casing, a time scale disc centered on thelongitudinal axis of said casing, a detonator charge in the casing, aprimer support pivoted eccentrically relative to the axis of the casingand spring urged toward said axis, a detonator charge in the casing -tobe activated by the primer, a clockwork in the casing; a timing shaftassembly in the casing and including a clock-driven member mounted forrotation only and a time setting member also mounted co-axially withsaid clock driven member and movable manually in both an angular and anaxial direction with respect to said clock driven member; a springloaded firing pin in the time setting member, and cooperating means onsaid time setting member and the clock driven member to lock the firingpin in a safe position and to release it after the expiration of aselected interval of time operation by the clockwork to explode theprimer.

2. A mechanical timing fuze according to claim 1, wherein the time scaledisc has peripheral teeth, and opposite spring biased levers havingtoothed inner portions normally engage said teeth, and the outer ends ofsaid levers are exposed for manual squeezing to release the disc to beturned by said time setting member.

3. A mechanical timing fuze according to claim 1, wherein the primersupport is held in safe position against the force of its spring by arestraining tooth on the clock driven member, said support having aprimer charge which is brought into registry with the firing pin as thesaid tooth moves away from the primer support.

4. A mechanical timing fuze according to claim 1, wherein, the clockdriven member is hollow and its upper end slidably and telescopicallyreceives the lower end of the time setting member.

5. A mechanical timing fuze according to claim 1, wherein the clockdriven member and the time setting member have telescopicallyinterfitting parts each provided with an opening radially and axiallyspaced from one another, and a locking member in the form of a ball istrapped between the opening of the time setting memher and the innerWall of the clock driven member until said clock driven member turnsangularly so that its opening registers with the opening in the timesetting member and the ball passes through both openings to release thefiring pin into engagement with the primer.

6. A mechanical timing fuze according to claim 1, wherein the timesetting member is provided with a cross bar, and a spring urged rod iscontrolled by said cross member to release the clockwork.

7. A mechanical timing fuze for an explosive submarine chargecomprising, in combination, a casing, a twopart timing shaft assemblymounted in said casing for relative axial and rotary movement andincluding a sliding member and a rotatable member, a notched primersupport normally spring urged to firing position, a firing pin disposedwithin the timing shaft and energized by a spring toward the primer, thepoint of said firing pin when the fuze is in the safe position restingin the notched portion of the support, releasable locking means betweenthe two parts, of the timing shaft assembly and normally inactive whenthe fuze is in a safe position and the firing pin is maintained out ofcontact with the primer, clock mechanism in the housing and including abalance wheel, cooperating safety locking means respectively on aportion of the casing and on the time setting shaft releasable upon theinitial turning of said time setting shaft and manual means for rotatingand axially moving said sliding member of said timing shaft, whereby,said clock mechanism will turn the rotatable member to release theprimer support and the firing pin upon the expiration of a preset timeinterval.

8. A mechanical timing fuze for an explosive submarine charge,comprising, in combination, a fuze body having a central borecommunicating with a recess on the exposed outer face of the body andalso having an inner attaching edge, a timing disc in said recess andhaving a central opening registering with said bore, said opening havinga radial notch, a fuze sheath having a side wall secured at one end tothe said inner attaching edge of the fuze body and having a well at theother end, a detonator charge in said well, a first plate and a secondplate disposed in spaced relation within the sheath and covering saidwell and providing a compartment, a spindle mounted between said plateseccentric to the axis of said bore, a primer support pivotally mountedon said spindle, a primer charge on the support, a spring nor mallyurging the support to move the primer in alignment with the axis of thebore, a third plate spaced from said second plate and a fourth platespaced from said third plate said last mentioned plates providingcompartments respectively for the main spring, balance wheel and geartrain of a clock mechanism, a timing shaft assembly including, an outertime setting section having an inner recessed end and fitted in saidbore, a hollow inner clock driven section having a portion telescopingover the recessed end of the outer section, said sections havingnormally non-registering holes, a driving pinion on the hollow innersection meshing with said gear train, a U- shaped fifth plate having asafety lip and spaced from the fourth plate, a guide post between thefourth and fifth plates, a cross member between the fourth and fifthplate and carried by the time setting section of the timing shaftassembly, a spring confined between said cross member and the fifthplate, a downwardly spring biased rod operated by said cross member forengaging and releasing said balance wheel, a safety shoulder on the timesetting shaft and normally engaged with said fifth plate, a firing pinhaving a collar slidably mounted in the recessed innor end of the timesetting shaft and spring biased toward the primer, said collar having abeveled end portion, a ball normally confined in opening of time settingshaft and the inner wall of the hollow clock driven section, a knobkeyed to the time setting shaft, a button having its head exposed at thetop of the knob, and a notched shank, and a detent radially movable insaid notch, whereby as the knob is rotated the shoulder on the timesetting shaft will move from beneath the safety lip on the fifth plateand permit the time setting shaft to be pulled axially outward to liftthe detent into the notch of disc and the cross member will lift saidrod to release the clock mechanism, and upon the expiration of theselected time interval said openings will register and the ball Will beprojected therethrough from the bevel edge of the collar to release thefiring pin and strike the primer.

References Cited in the file of this patent UNITED STATES PATENTS1,288,797 Asbury Dec. 24, 1918 2,325,749 Delay Aug. 3, 1943 2,369,310McGrath Feb. 13, 1945 2,514,499 Kharasch July 11, 1950 2,814,251 KuhnNov. 26, 1957 2,911,915 Gibbs Nov. 10, 1959

